diff --git a/extensions/apps-menu/extension.js b/extensions/apps-menu/extension.js
index 866bd9c7..a834330e 100644
--- a/extensions/apps-menu/extension.js
+++ b/extensions/apps-menu/extension.js
@@ -327,7 +327,7 @@ class DesktopTarget {
                 try {
                     o.set_attributes_finish(res);
                 } catch (e) {
-                    log('Failed to update access time: ' + e.message);
+                    log(`Failed to update access time: ${e.message}`);
                 }
             });
     }
@@ -354,7 +354,7 @@ class DesktopTarget {
                             this._touchFile(file);
                         });
                 } catch (e) {
-                    log('Failed to mark file as trusted: ' + e.message);
+                    log(`Failed to mark file as trusted: ${e.message}`);
                 }
             });
     }
@@ -392,7 +392,7 @@ class DesktopTarget {
             src.copy(dst, Gio.FileCopyFlags.OVERWRITE, null, null);
             this._markTrusted(dst);
         } catch (e) {
-            log('Failed to copy to desktop: ' + e.message);
+            log(`Failed to copy to desktop: ${e.message}`);
         }
 
         return true;
@@ -688,8 +688,8 @@ class ApplicationsButton extends PanelMenu.Button {
         let themeContext = St.ThemeContext.get_for_stage(global.stage);
         let scaleFactor = themeContext.scale_factor;
         let categoriesHeight = this.categoriesBox.height / scaleFactor;
-        let height = Math.round(categoriesHeight) + MENU_HEIGHT_OFFSET + 'px';
-        this.mainBox.style+=('height: ' + height);
+        let height = Math.round(categoriesHeight) + MENU_HEIGHT_OFFSET;
+        this.mainBox.style += `height: ${height}px`;
     }
 
     selectCategory(dir) {
diff --git a/extensions/auto-move-windows/prefs.js b/extensions/auto-move-windows/prefs.js
index 56f50e74..893cc6d5 100644
--- a/extensions/auto-move-windows/prefs.js
+++ b/extensions/auto-move-windows/prefs.js
@@ -216,12 +216,12 @@ const Widget = GObject.registerClass({
 
     _checkId(id) {
         let items = this._settings.get_strv(SETTINGS_KEY);
-        return !items.some(i => i.startsWith(id + ':'));
+        return !items.some(i => i.startsWith(`${id}:`));
     }
 
     _appendItem(id, workspace) {
         let currentItems = this._settings.get_strv(SETTINGS_KEY);
-        currentItems.push(id + ':' + workspace);
+        currentItems.push(`${id}:${workspace}`);
         this._settings.set_strv(SETTINGS_KEY, currentItems);
     }
 
@@ -240,9 +240,9 @@ const Widget = GObject.registerClass({
         let index = currentItems.map(el => el.split(':')[0]).indexOf(id);
 
         if (index < 0)
-            currentItems.push(id + ':' + workspace);
+            currentItems.push(`${id}:${workspace}`);
         else
-            currentItems[index] = id + ':' + workspace;
+            currentItems[index] = `${id}:${workspace}`;
         this._settings.set_strv(SETTINGS_KEY, currentItems);
     }
 });
diff --git a/extensions/places-menu/extension.js b/extensions/places-menu/extension.js
index e9e9914a..968a45ee 100644
--- a/extensions/places-menu/extension.js
+++ b/extensions/places-menu/extension.js
@@ -91,7 +91,7 @@ class PlacesMenu extends PanelMenu.Button {
         for (let i = 0; i < SECTIONS.length; i++) {
             let id = SECTIONS[i];
             this._sections[id] = new PopupMenu.PopupMenuSection();
-            this.placesManager.connect(id + '-updated', () => {
+            this.placesManager.connect(`${id}-updated`, () => {
                 this._redisplay(id);
             });
 
diff --git a/extensions/user-theme/extension.js b/extensions/user-theme/extension.js
index 24a34a71..9a0bd215 100644
--- a/extensions/user-theme/extension.js
+++ b/extensions/user-theme/extension.js
@@ -17,7 +17,7 @@ class ThemeManager {
     }
 
     enable() {
-        this._changedId = this._settings.connect('changed::'+SETTINGS_KEY, this._changeTheme.bind(this));
+        this._changedId = this._settings.connect(`changed::${SETTINGS_KEY}`, this._changeTheme.bind(this));
         this._changeTheme();
     }
 
@@ -59,7 +59,7 @@ class ThemeManager {
         }
 
         if (_stylesheet)
-            global.log('loading user theme: ' + _stylesheet);
+            global.log(`loading user theme: ${_stylesheet}`);
         else
             global.log('loading default theme (Adwaita)');
         Main.setThemeStylesheet(_stylesheet);
diff --git a/extensions/window-list/prefs.js b/extensions/window-list/prefs.js
index 8cc90f12..f7bb3ee0 100644
--- a/extensions/window-list/prefs.js
+++ b/extensions/window-list/prefs.js
@@ -25,7 +25,7 @@ class WindowListPrefsWidget extends Gtk.Grid {
         this.row_spacing = 6;
         this.orientation = Gtk.Orientation.VERTICAL;
 
-        let groupingLabel = '<b>' + _("Window Grouping") + '</b>';
+        let groupingLabel = '<b>%s</b>'.format(_("Window Grouping"));
         this.add(new Gtk.Label({ label: groupingLabel, use_markup: true,
                                  halign: Gtk.Align.START }));
 
diff --git a/extensions/workspace-indicator/extension.js b/extensions/workspace-indicator/extension.js
index bd36b779..cdd841ba 100644
--- a/extensions/workspace-indicator/extension.js
+++ b/extensions/workspace-indicator/extension.js
@@ -53,7 +53,7 @@ class WorkspaceIndicator extends PanelMenu.Button {
 
         this._settings = new Gio.Settings({ schema_id: WORKSPACE_SCHEMA });
         this._settingsChangedId =
-            this._settings.connect('changed::' + WORKSPACE_KEY,
+            this._settings.connect(`changed::${WORKSPACE_KEY}`,
                                    this._createWorkspacesSection.bind(this));
     }
 
diff --git a/extensions/workspace-indicator/prefs.js b/extensions/workspace-indicator/prefs.js
index 73c44f80..3a70eaa7 100644
--- a/extensions/workspace-indicator/prefs.js
+++ b/extensions/workspace-indicator/prefs.js
@@ -130,7 +130,7 @@ class WorkspaceSettingsWidget extends Gtk.Grid {
         this.margin = 12;
         this.orientation = Gtk.Orientation.VERTICAL;
 
-        this.add(new Gtk.Label({ label: '<b>' + _("Workspace Names") + '</b>',
+        this.add(new Gtk.Label({ label: '<b>%s</b>'.format(_("Workspace Names")),
                                  use_markup: true, margin_bottom: 6,
                                  hexpand: true, halign: Gtk.Align.START }));
 
diff --git a/lib/convenience.js b/lib/convenience.js
index bbc86081..4775eddb 100644
--- a/lib/convenience.js
+++ b/lib/convenience.js
@@ -85,9 +85,9 @@ function getSettings(schema) {
 
     let schemaObj = schemaSource.lookup(schema, true);
     if (!schemaObj)
-        throw new Error('Schema ' + schema + ' could not be found for extension '
-                        + extension.metadata.uuid + '. Please check your installation.');
+        throw new Error(
+            `Schema ${schema} could not be found for extension ${extension.metadata.uuid}. Please check your installation.`
+        );
 
     return new Gio.Settings({ settings_schema: schemaObj });
 }
-